Recently vehicle steering devices have been proposed that provide so-called steer-by-wire (hereafter, “SBW”) systems and disengage the mechanical link between the steering wheel and the vehicle turning wheels to activate a steering system employing an electronic route. With these types of SBW mechanisms, it is important to provide a fail-safe countermeasure to deal with instances in which, for example, an irregularity arises in the actuator used for steering reaction force. In this regard, in instances of irregularity, system check, failure diagnosis, or maximum turning angle execution, configurations have been proposed that function as a regular electromotive power steering device (hereafter, “EPS”), which suspends control by a reaction force controller, engages a backup mechanism for mechanically linking the steering members and the vehicle turning wheels, switches control in order to provide steering assistance to the steering control component, and controls the turning actuator. See, for example, Japanese Laid-open Patent Application No. 2004-090783, published Mar. 25, 2004 (filed Aug. 30, 2002).